The present study investigated a simple ecofriendly approach for synthesis of zinc oxide (ZnO) nanoparticles using aqueous plant extracts of leafy vegetable plants Peperomia pellucida and Celosia argentea. The plant extracts were acts as reducing and capping agent, while Zinc nitrate hexahydrate [Zn(NO₃)₂.6H₂O] was used as a precursor. The formation of ZnO nanoparticles were confirmed by visual observation followed by UV-Visible spectral analysis. The absorbance peaks for P. pellucida leaf, stem and roots was 299 nm, 299 nm and 293 nm. The absorption peaks located at 342 nm, 304 nm and 308 nm for leaf, stem and roots of Celosia argentea respectively. The results confirmed that these two herbs could be exploited for the production of valuable ZnO nanoparticles at room temperature, which can overcome the hazardous issues related to the chemical, physical and conventional methods of nanoparticles synthesis.